JPH11223546A - Presence/absence detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inexpensive presence/absence detector with high quality and high durability for detecting the presence/absence of a patient. SOLUTION: This presence/absence detector is provided with a sensor case 5 having plural protrusions on an eccentric circumference for detecting the presence/absence of a patient in bedding according to weight imposed on the bedding, sensor board 6 on whose lower face a distortion sensing resistor is attached on the sensor case 5, pressurizing body 2 having a protrusion for pushing the opposite face to which the distortion sensing resistor is attached, and having a circular-arc face-shaped recessed part on the upper face on the sensor substrate 6, and a cover member 3 for covering the sensor case 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a hospital, a nursing home,
The present invention relates to an in-bed detection device used in various facilities such as a nursing care facility, or home nursing, nursing care, and the like, and particularly relates to a device for detecting a state of a person on bedding. The on-bed detection device of the present invention is used, for example, for remotely knowing whether or not a patient is on bedding.

[0002]

2. Description of the Related Art In nursing homes and facilities for accommodating persons with intellectual disabilities, there is a danger that the inmates will wander at night, and sufficient monitoring is required. Also in a normal hospital, it is important to confirm whether or not a patient is on bedding (bed). Therefore, in hospitals and the like, it is necessary to know whether an inpatient is sleeping on bedding or leaving the bed at night or the like.

[0003] However, it is virtually impossible to constantly look around the bedding of all hospitalized patients, requiring a considerable number of nurses. In order to solve this problem, Japanese Unexamined Patent Publication No. Hei 6-125828 discloses a bed detection device that remotely detects whether or not a person is on the bed.

Hereinafter, with reference to the accompanying drawings,
The on-bed detection device disclosed in Japanese Patent No. 5828 will be described. FIG. 23 is a configuration diagram showing an entire system of a conventional bed detection device, and FIG. 24 is a cross-sectional view of the bed detection device incorporated in bedding. In FIG. 23, 2
Reference numeral 11 denotes a bedding main body including a mat 213 and a bottom 215. Legs 217 are provided at six locations on the bottom surface of the bottom 215 of the bedding body 211 at predetermined intervals. In the related art, the above-described leg 217 is used.
Has not only a function of supporting the bedding body 211 but also a function of detecting whether or not a person is present on the bedding.

[0005] That is, the leg 217 has a telescopic structure, and it is detected whether or not there is a person on the bedding according to the degree of the telescopic. More specifically, the leg 217 is provided as shown in FIG.
As shown in FIG. 4, the bottom 215 is fixed to the lower plate frame 225 via the screw portion 227. A cylindrical portion 229 is formed downward on the upper leg portion 233 provided with the screw portion 227. On the other hand, a cylindrical portion 224 is formed upward from the lower leg portion 231 which is in contact with the floor surface, and the cylindrical portion 224 is connected to the upper leg portion 2 described above.
It is movably accommodated in 33 cylindrical portions 229.

A compression spring 235 is disposed outside the cylindrical portion 229 of the upper leg portion 233. The upper end of the compression spring 235 is in contact with the flange 237 of the upper leg portion 233, and the lower end is located at the lower leg portion. It is in contact with the part 231. Therefore, the leg 217 expands and contracts as a whole. A cover member 239 is disposed outside the compression spring 235. The slider 241 is provided inside the leg 217.
And a sliding resistance wire 243 are built in. That is, the slider 241 has its upper end fixed to the center of the upper leg 233,
It is arranged so as to hang downward. The slider 241 is provided with a contact 245. On the other hand, on the lower leg 231 side, a sliding resistance wire 243 is disposed facing upward, and the lower end of the sliding resistance wire 243 is fixed to the lower leg 231. And the sliding resistance wire 243
, The contact 245 of the above-mentioned slider 241 is in contact. A compression spring 251 is additionally provided between the upper leg 233 and the lower leg 231.

The operation of the thus constructed bedding will be described below. When a person rides on the bedding, a load is applied to the upper leg 233 of each leg 217. This load causes the upper leg 233 to move downward against the compression springs 235 and 251, and
The 41 contacts 245 move downward along the sliding resistance line 243, and the resistance between the contacts A and B of the electric circuit decreases. Therefore, by measuring the resistance between the contact points A and B, it can be determined whether or not a person is on the bedding. Therefore, in the related art, the electric wire 249 is connected between the contacts A and B and the controller 247, and the resistance between the contacts A and B is remotely measured to determine whether or not a person is on the bedding.

[0008]

However, the above-mentioned conventional on-bed detection device has a complicated structure because a slider or a sliding resistance wire is built in the leg of the bedding. Further, the conventional occupancy detection device is provided in a vertically movable part and measures the resistance value by mechanical contact, so that there are many failures and malfunctions. In addition, when trying to centrally manage multiple beddings using prior art devices,
The load obtained via a sliding resistor or the like is subjected to signal processing, the signal is transmitted to the detection device, and the presence or absence of a person is determined by comparing the signal with a reference value specified separately. As described above, in the related art, since a signal processing circuit and the like are required, the configuration of the entire system becomes complicated and expensive. Further, in the bed detection device of the related art, since the load sensor is incorporated in the leg portion of the bedding, a wiring is connected to the bedding, and there is a disadvantage that the bedding cannot be freely moved. The present invention solves the problems of the prior art, provides an inexpensive on-bed detection device that detects the presence or absence of a patient and has high quality and excellent durability, and provides a mental and physical burden to caregivers and nurses. It is intended to reduce

[0009]

According to the present invention, there is provided a pressure body which receives a load of a bedding, and a strain-sensitive resistor provided on at least one surface and pressed by the pressure body. An on-bed detection device including a sensor substrate, a sensor case supporting the sensor substrate, and an electric circuit for outputting an electric signal corresponding to a resistance value between terminals of the strain-sensitive resistor to the outside.

Thus, it is possible to judge the presence or absence of a person on the bedding by comparing the output of the bed detection device with the output value when no person is on the bedding outside. In addition, this makes it possible to provide a high-quality and highly reliable occupancy detection device.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention is directed to a pressure sensor which receives a load of bedding and a sensor which is provided with a strain-sensitive resistor on at least one surface and which is pressed by the pressure member. An on-bed detection device including a substrate, a sensor case supporting the sensor substrate, and an electric circuit for outputting an electric signal corresponding to a resistance value between terminals of the strain-sensitive resistor to the outside.

In the bed detection device of the present invention, the load of the bedding is received by the pressing body, and the sensor substrate is pressed via the pressing body. Then, the strain-sensitive resistor attached to the sensor board detects the strain generated on the sensor board, and the resistance value of the strain-sensitive resistor changes according to the strain. Further, in the present invention, the electric circuit outputs an electric signal corresponding to the resistance value between the terminals of the strain-sensitive resistor to the outside. Then, it is determined whether or not a person is on the bedding based on the electric signal. In the occupancy detection device of the present invention, the presence or absence of occupancy is determined by the strain-sensitive resistor, so that the signal processing circuit can be simplified. In addition, the on-bed detection device of the present invention has few failures because it has few movable parts.

According to a second aspect of the present invention, there is provided a sensor case having a plurality of projections or one or more recesses, and supporting at least a part of the sensor substrate in a hollow manner. An on-bed detection device according to claim 1.

[0014] In the presence detection device of the present invention, the sensor case has a plurality of protrusions or one or more recesses, and at least a part of the sensor substrate is supported in a hollow state. Therefore, the sensor substrate is supported in a state of being easily deformed, and has a large distortion. Therefore, the bed detection device of the present invention has high detection accuracy.

According to a third aspect of the present invention, the pressing body is provided with a projection, and the projection presses the sensor substrate.
Or the occupancy detection device according to 2.

In the presence detection device of the present invention, since the sensor substrate is pressed by the projection, a concentrated load is applied to the sensor substrate. Therefore, the amount of deformation of the sensor substrate is large, and the detection accuracy is high.

According to a fourth aspect of the present invention, in which the above-mentioned invention is further improved, the strain-sensitive resistor is provided on the lower surface of the sensor substrate, and the projection of the pressing body is provided on the upper surface of the sensor substrate. 4. The on-bed detection device according to claim 1, wherein an upper portion of the resistor is pressed.

In the bed detection device of the present invention, the strain-sensitive resistor is provided on the lower surface of the sensor substrate, and the projection of the pressing body presses the upper surface of the sensor substrate. Therefore, the strain-sensitive resistor is not damaged by the protrusion of the pressing body. Further, in the present invention, the back side of the strain-sensitive resistor is pressed by the projection of the pressure body, so the strain-sensitive resistor is located at the portion where the distortion is largest, and the detection accuracy of whether or not a person is present is high. high.

According to a fifth aspect of the present invention, a plurality of strain-sensitive resistors are disposed on the sensor substrate at the same circumferential interval, and the sensor case is provided on the sensor case. The floor presence detection device according to any one of claims 1 to 4, wherein a projection that supports between the bodies or a concave portion that forms a space is provided in a portion where the strain-sensitive resistor is attached. .

In the on-bed detection device according to the present invention, a plurality of strain-sensitive resistors are arranged at intervals around the same circumference. Therefore, in the bed detection device of the present invention, when an uneven load is applied to the pressurized body, the direction of the load and the like are detected. Therefore,
In the occupancy detection device of the present invention, the position and posture of the patient or the like on the bedding, more specifically, whether the patient is lying near the edge of the bedding, sleeping in the center, sitting, or turning over Can also be detected.

According to a sixth aspect of the present invention, which is an improvement of the above-described aspect, a first strain-sensitive resistor, a second strain-sensitive resistor, a third strain-sensitive resistor, Fourth strain-sensitive resistors are arranged at 90 ° intervals on the same circumference, and the electric circuit includes a fourth strain-sensitive resistor having one end connected to GND and the other end connected to one end of the fourth strain-sensitive resistor. A first voltage-dividing circuit including a voltage-dividing resistor and the fourth strain-sensitive resistor having the other end connected to a voltage power supply, and a first voltage-dividing circuit having one end connected to the voltage power supply and the other end connected to the second power supply. A second voltage-dividing circuit including a third voltage-dividing resistor connected to one end of the strain resistor, the second strain-sensitive resistor having the other end connected to GND, and one end connected to GND And a second end connected to one end of the third strain-sensitive resistor.
A third voltage-dividing circuit including a voltage-dividing resistor, and the third strain-sensitive resistor having the other end connected to a voltage power supply; and a third voltage-dividing circuit having one end connected to a voltage power supply and the other end connected to the first power supply. A fourth voltage dividing circuit including a first voltage-dividing resistor connected to one end of the strain resistor, the first strain-sensitive resistor having the other end connected to GND, and the second voltage sensing circuit. A first differential amplifier circuit for outputting a voltage value proportional to a voltage value obtained by subtracting a voltage value applied between the terminals of the fourth voltage-dividing resistor from a voltage value applied between the terminals of the strain resistor; A second differential amplifier circuit that outputs a voltage value proportional to a voltage value obtained by subtracting a voltage value applied between the terminals of the second voltage-dividing resistor from a voltage value applied between the terminals of the first strain-sensitive resistor; An adder circuit for adding an output voltage value of the first differential amplifier circuit and an output voltage value of the second differential amplifier circuit. Is the bed detection device according to any one of claims 1 to 5, characterized.

In the floor-bed detecting device of the present invention, since the strain-sensitive resistors are arranged on the sensor substrate at 90 ° intervals on the same circumference, the weight applied to the pressing body is divided into four parts by the strain-sensitive body. The applied load can be detected by the link structure.

According to a seventh aspect of the present invention, further improved from the above invention, the sensor board is made of an elastic body. It is.

In the bed detection device of the present invention, since the sensor substrate is made of an elastic body, it easily bends under the load from the pressurizing body, and the sensor substrate is greatly deformed and the detection accuracy is high. . When the load is removed, the state returns to the original state, and the repetition accuracy is high.

According to an eighth aspect of the present invention, the sensor substrate has a metal substrate and an insulating glass layer provided on the metal substrate. 8. A sensing circuit for detecting a change in resistance of a strain-sensitive resistor, an electrode for transmitting a signal, and a strain-sensitive resistor on the layer. Is an on-bed detection device.

In the presence detection device of the present invention, a metal base is used as a main material of the sensor base. In the presence detection device of the present invention, since the sensor base is made of metal, it has elasticity, high detection accuracy, and high repetition accuracy. In addition, it is necessary to insulate the surface of the base material because a metal is used for the sensor base material and a detection circuit is formed on the surface, but in the present invention, by providing an insulating glass layer on the surface, the base material is provided. Insulation is ensured. Also, in the present invention, since glass is particularly adopted as the insulating material,
The distortion of the sensor substrate is easily transmitted to the strain-sensitive resistor, and the detection accuracy is high. That is, when the detection circuit is provided, it is necessary to heat the base material. However, glass has a coefficient of thermal expansion close to that of a metal, and is less likely to be peeled off when the base material is heated. Is high. Further, the metal base, the insulating glass layer and the strain-sensitive resistor and the electrode body can be chemically bonded to each other, and the integrity of the base and the strain-sensitive resistor can be further improved. Therefore, the integration is higher, the distortion of the sensor substrate is easily transmitted to the strain-sensitive resistor, and the detection accuracy is high.

According to a ninth aspect of the present invention, which is a further improvement of the above-described aspect, the sensor substrate has a main body and a peninsula-shaped pressure-sensitive portion having a width narrower than the main body, and both are connected by a constricted portion. The floor-mounted floor according to any one of claims 1 to 8, wherein a strain-sensitive resistor is provided in the pressure-sensitive portion, and the strain-sensitive resistor is wired to the main body through a narrowed portion. It is a detection device.

In the occupancy detection device of the present invention, the sensor substrate has a main body and a peninsula-shaped pressure-sensitive portion having a width smaller than that of the main body, and a strain-sensitive resistor is provided in the peninsula-shaped pressure-sensitive portion. ing. Therefore, the pressure-sensitive portion is easily deformed, and the detection accuracy is high. Further, since the pressure-sensitive portion is connected to the main body at the constriction, the main body is less affected by the deformation of the pressure-sensitive portion.

[0029] Claim 10 which further improves the above-mentioned invention.
The protrusions of the sensor case are provided at equal intervals on the circumference, and the sensor substrate has a base layer and an insulating layer and is a substrate mounted on the protrusions of the sensor case. A pressure sensing portion having a circular or polygonal ring shape, wherein the pressure sensing portion is on a straight line connecting the center of the pressure sensing portion and the projection and is disposed on an outer peripheral side of the projection. And four strain-sensitive resistors are arranged at 90 ° intervals on the lower surface of the pressure-sensitive portion and on the circumference of the ring, and the two strain-sensitive resistors are disposed on two adjacent ones of the sensor case. The occupancy detection device according to claim 1, wherein the occupancy detection device is located between the protrusions.

The bed detection device of the present invention includes a circular or polygonal ring-shaped pressure-sensitive portion, and the pressure-sensitive portion is on a straight line connecting the center of the pressure-sensitive portion and the projection of the sensor case. And supported via a connecting portion arranged on the outer peripheral side of the projection. That is, since the connecting portion is located immediately adjacent to the protrusion of the sensor case, the bending moment applied to the connecting portion is small. In addition, four strain-sensitive resistors are arranged at 90 ° intervals on the lower surface of the pressure-sensitive portion and on the circumference of the ring, and the strain-sensitive resistors are:
The sensor case is located between two adjacent protrusions. That is, the strain-sensitive resistor is provided at an intermediate portion between the protrusions of the sensor case. In other words, the strain-sensitive resistor is provided between the support ends of the ring where the amount of deformation is the largest. Therefore, the strain-sensitive resistor is located in a portion where the distortion is the largest, and the detection accuracy of whether or not a person is present is high.

[0031] Claim 11 which further improves the above-mentioned invention.
11. The invention according to claim 1, wherein the electric circuit has a voltage-dividing resistor, and the voltage-dividing resistor is made of the same material as the strain-sensitive resistor. Is an on-bed detection device.

In the on-bed detection device of the present invention, a voltage-dividing resistor made of the same material as the strain-sensitive resistor is provided.
Therefore, the temperature dependence of the resistance value of the strain-sensitive resistor and the resistance value of the voltage-dividing resistor substantially match, and there is no need for temperature correction.

The twelfth aspect of the present invention is a further improvement of the above invention.
The invention described in (1) has a cover member provided with an opening in a part thereof and covering an upper surface of the sensor case, a part of the pressure body is exposed to the outside from the cover member, and the other part is covered by the cover member. The occupancy detection device according to any one of claims 1 to 11, wherein:

Since the presence detection device of the present invention has a cover member and the sensor case is covered by the cover member, dust does not enter the sensor case and malfunctions are reduced.

Further, the present invention is summarized in claim 13.
The invention described in (1) provides a sensor case in which four protrusions are provided at 90 ° intervals on a concentric circle substantially at the center of the inner bottom surface of the case opened upward, a metal base and an insulating glass layer covering the surface of the metal base. A substrate mounted on the protrusion of the sensor case, the pressure-sensitive portion having a circular or polygonal ring shape, and a straight line connecting the center of the ring of the pressure-sensitive portion and the protrusion. And a circuit portion supporting the pressure-sensitive portion via a connecting portion disposed on the upper side and on the outer peripheral side of the projection. An elastically deformable sensor substrate having a resistor attached between two adjacent protrusions of the sensor case; and a resistor mounted on the upper surface of the sensor substrate and substantially at the center of the lower surface.
A pressurizing body having two projections disposed so as to abut against the side surface of the sensor substrate opposite to the location where the strain-sensitive resistor is attached, and having a recess formed at substantially the center of the upper surface for mounting one leg of the bedding; A sensor case cover having an opening for exposing an upper surface of the pressurizing body and covering an upper surface opening of the sensor case, wherein the strain-sensitive resistor and the circuit portion of the pressure-sensitive portion of the sensor substrate are The circuit portion is connected by a conductor pattern wired so as not to come into contact with the protrusion of the sensor case through the lower surface of the connection portion, and the circuit portion is formed of the same material as the strain-sensitive resistor of the pressure-sensitive portion. A fourth voltage-dividing resistor having one end connected to GND and the other end connected to one end of the fourth strain-sensitive resistor; and the other end connected to a voltage power supply. A first voltage dividing circuit comprising the fourth strain-sensitive resistor. A third voltage-dividing resistor having one end connected to a voltage power supply and the other end connected to one end of the second strain-sensitive resistor, and the second strain-sensitive resistor having the other end connected to GND. A second voltage-dividing circuit composed of a body, a second voltage-dividing resistor having one end connected to GND and the other end connected to one end of the third strain-sensitive resistor, and the other end connected to a voltage power supply. A third voltage-dividing circuit including the third strain-sensitive resistor connected thereto, and a first voltage-dividing circuit having one end connected to a voltage power supply and the other end connected to one end of the first strain-sensitive resistor. A fourth voltage-dividing circuit including a pressure resistor and the first strain-sensitive resistor having the other end connected to GND; and a fourth voltage-dividing circuit configured to calculate the voltage based on a voltage value applied between terminals of the second strain-sensitive resistor. A first differential amplifier circuit for outputting a voltage value proportional to a voltage value obtained by subtracting a voltage value applied between terminals of the voltage-dividing resistor, and a first strain-sensitive resistor A second differential amplifier circuit that outputs a voltage value proportional to a voltage value obtained by subtracting a voltage value applied between the terminals of the second voltage-dividing resistor from a voltage value applied between the terminals; An occupancy detection device comprising an adding circuit for adding an output voltage value of an amplifier circuit and an output voltage value of the second differential amplifier circuit.

The present invention has almost all of the features of the invention described in claims 1 to 12, and presses a sensor substrate via a pressing body to detect distortion generated in the sensor substrate. If the detected distortion is large, it is determined that there is a person on the bedding, and if the distortion is small, it is determined that there is no person. In the presence detection device of the present invention, whether or not the person is in the presence of the floor is determined by the strain-sensitive resistor, so that the signal processing circuit can be simplified. In addition, the on-bed detection device of the present invention has few failures because it has few movable parts. Further, the bed detection device of the present invention includes a circular or polygonal ring-shaped pressure-sensitive portion, wherein the pressure-sensitive portion is on a straight line connecting a center of the pressure-sensitive portion and a protrusion of the sensor case, and It is supported via a connecting portion arranged on the outer peripheral side of the projection. That is, since the connecting portion is located immediately adjacent to the protrusion of the sensor case, the bending moment applied to the connecting portion is small. In the occupancy detection device of the present invention, the sensor substrate has a circuit portion, and the circuit portion is provided with an amplifier circuit and the like, but the pressure-sensitive portion and the circuit portion are connected by a connection portion, and the connection portion Since the generated bending moment is small, the bending moment transmitted to the circuit portion is small. Therefore, even if the pressure-sensitive part is pressed by the pressing body,
There is little deformation of the circuit part. Further, in the present invention, four strain-sensitive resistors are arranged at 90 ° intervals on the lower surface of the pressure-sensitive portion and on the circumference of the ring, and the strain-sensitive resistors are arranged adjacent to the sensor case. Located between the two protrusions. That is, the strain-sensitive resistor is provided at an intermediate portion between the protrusions of the sensor case. In other words, the strain-sensitive resistor is provided between the support ends of the ring where the amount of deformation is the largest. Therefore, the strain-sensitive resistor is located in a portion where the distortion is the largest, and the detection accuracy of whether or not a person is present is high. Further, in the present invention, as described above, four strain-sensitive resistors are provided at positions on the circumference of the ring.
The strain-sensitive resistors are arranged at intervals of 0 °, and the strain-sensitive resistors are located between two adjacent protrusions of the sensor case. Therefore, when an uneven load is applied to the pressing body, the direction of the load is detected. It is also possible. Therefore, in the bed detection device of the present invention, the position or posture of the patient on the bedding, more specifically,
It is also possible to detect whether the user is sleeping near the edge of the bedding, sleeping at the center, sitting, or turning over. In addition, since the bed detection device of the present invention also has the cover member, dust does not enter the sensor case, and there is little malfunction or the like. Further, in the bed detection device of the present invention, the strain-sensitive resistor and the circuit portion of the pressure-sensitive portion of the sensor board are connected by a conductor pattern wired so as to pass through the lower surface of the connecting portion and not to contact the projection of the sensor case. Therefore, the pressure-sensitive portion and the circuit portion can be electrically connected, and there is no disconnection or short-circuit due to abutment of the projection. In addition, by configuring the conductor pattern so as not to contact the protrusion of the support, a lead wire for connecting the strain-sensitive resistor and the detection circuit is not required, which not only reduces the cost but also prevents erroneous detection due to noise. Can be. In the circuit section, a voltage-dividing resistor corresponding to each strain-sensitive resistor of the pressure-sensitive section, a plurality of voltage-dividing circuits including the strain-sensitive resistor and the voltage-dividing resistor, A differential amplifier circuit or the like having an output as an input is arranged, and the voltage-dividing resistor of the voltage-dividing circuit is made of the same material as the strain-sensitive resistor of the pressure-sensitive section. In addition, the dependence of the resistance value of the voltage-dividing resistor of the circuit portion on the temperature can be made substantially the same, and the dispersion of the zero point characteristics can be reduced.

[0037] Further, the above-mentioned invention is improved.
The pressing body covers the upper side of the sensor substrate, and has a wall portion hanging down on the lower surface of the pressing body so as to surround the sensor substrate.
The presence detection device according to any one of the above.

In the presence detection device of the present invention, since the sensor substrate is covered with the pressurized body, it is possible to prevent water droplets, detergent liquid, etc. from directly hitting the sensor substrate. An on-bed detection device can be realized.

A further improvement of the above-mentioned invention.
According to the invention described in the above, a projection is provided at a lower part of the pressure body of the sensor case, and when a load equal to or more than a certain amount or an uneven load is applied to the pressure body, a part of the pressure body is The occupancy detection device according to any one of claims 1 to 14, which is in contact with the occupancy detection device.

According to a sixteenth aspect of the present invention, a projection is provided on the lower surface of the pressing body, and when a certain load or an uneven load is applied to the pressing body, the projection is in the sensor case. The occupancy detection device according to any one of claims 1 to 15, which is in contact with a part of the occupancy detection device.

The invention according to claims 15 and 16 protects the sensor substrate and the like when an excessive force is applied to the pressure body. That is, in the bed detection device according to claim 15, when a load equal to or more than a certain value or an uneven load is applied to the pressing body, a part of the pressing body is provided below the pressing body of the sensor case. It abuts on the projection to prevent an excessive force from being applied to the sensor substrate. In the bed detection device according to claim 16, when a load equal to or more than a certain amount or an unbalanced load is applied to the pressurized body, the protrusion provided on the lower surface of the pressurized body contacts a part of the sensor case, An excessive force is prevented from being applied to the sensor substrate.

According to a seventeenth aspect of the present invention, the bedding is linearly guided from one side of the pressing body to the other side, and the pressing body has four projections. ,
The side of the square formed by cutting the center of the projection is perpendicular or parallel to the guiding direction of the bedding, and the sensor substrate has four strain-sensitive resistors at positions corresponding to the four projections of the pressing body. The detection circuit provided for detecting a change in the resistance value of the strain-sensitive resistor has two sets of bridge circuits, and a set of strain-sensitive resistors pressed by diagonally positioned protrusions is provided. The occupancy detection device according to any one of claims 1 to 16, wherein the occupancy detection device is incorporated in a bridge circuit.

In order to accurately detect a change in the weight of the bedding, the resistance values of the plurality of strain-sensitive resistors are changed so that the resistance values change evenly.
It is desirable to apply a load. For this purpose, it is recommended that the protrusion of the pressing body has a rectangular side formed so as to surround the center of the protrusion and is perpendicular or parallel to the guiding direction of the bedding. That is, contrary to the configuration of the present invention, when the diagonal of the square formed by cutting the center of the projection matches the guiding direction of the bedding, the load points may be concentrated on one projection. Further, in the bed detection device of the present invention, since the sides of the rectangle formed by connecting the center of the projection are perpendicular or parallel to the guiding direction of the bedding, the load points of the bedding do not concentrate on one projection. In addition, the presence detection device of the present invention solves this problem by devising a circuit for a bias value on the left and right sides with respect to the traveling direction. In the bed detection device of the present invention, as described above, the bedding is linearly guided from one of the pressing bodies toward the other. When the bedding is guided in this manner, the bias value of the load point occurs in the left and right directions with respect to the traveling direction. For example, a situation may occur in which only the strain-sensitive resistor on one side reacts with the center and the resistance value of the strain-sensitive resistor on the other side does not change. On the other hand, in the occupancy detection device of the present invention, the detection circuit for detecting the change in the resistance value has two sets of bridge circuits, and the strain-sensitive resistor pressed by the diagonally located protrusion is used. A set is incorporated in the bridge circuit. Therefore, even in the case of an extreme bias value such that only one strain-sensitive resistor reacts with respect to the center, the two sets of bridge circuits include a strain-sensitive resistor whose resistance value greatly changes, A strain-sensitive resistor having a small change in resistance value is combined and electrically complemented. Therefore, in the on-bed detection device of the present invention, a bias error with respect to the load applied to the strain-sensitive resistor can be reduced.

According to a further aspect of the present invention, there is provided an on-bed detection device according to any one of claims 1 to 17, wherein a wheel guiding slope is provided in the sensor case. is there.

The bed detection device of the present invention facilitates the bedding guidance by providing the sensor case with the wheel guiding slope.

[0046] Claim 19 which further improved the above-mentioned invention.
The present invention according to any one of claims 1 to 18, wherein the groove for guiding a wheel or a mountain is provided on a wheel guiding slope of the sensor case.

In the presence detection device according to the present invention, the sensor case is provided with a groove or a mountain serving as a wheel guide on the wheel guiding slope, thereby regulating the wheel and guiding the wheel easily to the pressurized body, thereby facilitating the bedding. An occupancy detection device that can be installed can be realized.

According to a twentieth aspect of the present invention, the pressure body has a spherical portion, a base in contact with the spherical portion is provided, and a part of the bedding is provided on the base. 20. The occupancy detection device according to any one of claims 1 to 19, wherein

In the bed detection device of the present invention, the pressurizing body is provided with a spherical portion, and a platform in contact with the spherical portion is provided so that a part of the bedding is placed on the platform. It can be adjusted to the wheel of the bedding, the regulation of the wheel fixing position can be eliminated, and the error due to the fixing position can be reduced.

According to a twenty-first aspect of the present invention, the mounting holes provided in the sensor substrate and the projections of the sensor case inserted into the mounting holes are arranged at equal intervals on the same circumference. 3. The method according to claim 1, wherein
0. The occupancy detection device according to any one of claims 1 to 7.

In the presence detection device according to the present invention, the mounting holes provided in the sensor substrate and the projections of the sensor case inserted into the mounting holes are arranged at equal intervals on the same circumference, thereby mounting the sensor substrate. The direction can be changed, and the mounting efficiency of the on-bed detection device can be increased.

A further improvement of the above-mentioned invention.
The bedding is a bed having four or more legs, and the presence detection device according to any one of claims 1 to 21 is disposed between the legs and the floor. An occupancy detection device characterized in that:

In order to achieve the same object, a second aspect of the present invention is provided.
According to a third aspect of the present invention, the bedding is a bed having four or more legs, and the presence detection device according to any one of the first to twenty-first aspects is provided between the one leg and the floor. An occupancy detection device characterized by being arranged.

In the occupancy detection device according to the present invention, since the occupancy detection device is disposed between the leg of the bed and the floor, the change in the weight of the bed can be directly detected. It is possible to accurately detect whether or not a person is on the bed.

According to a twenty-fourth aspect of the present invention, the electric signal is a voltage corresponding to a resistance value between terminals of the strain-sensitive resistor.
3. The presence detection device according to any one of 3.

According to a twenty-fifth aspect of the present invention, in which the above-described invention is improved, the electric circuit has one end connected to GND, the other end connected to one end of the strain-sensitive resistor, and a terminal between the terminals of the strain-sensitive resistor. A voltage-dividing resistor having a resistance value sufficiently smaller than the resistance value, the strain-sensitive resistor having the other end connected to a voltage power supply, and a voltage applied between terminals of the voltage-dividing resistor, amplified to the outside. The occupancy detection device according to any one of claims 1 to 24, further comprising an output amplifier.

In the present invention, the voltage applied between the terminals of the voltage-dividing resistor is “Vcc × r / (R + r)”. Here, if r≪R, the voltage “Vcc ×
“r / (R + r)” can be approximated by Vcc × r / R. If R is proportional to the load, the amplifier outputs a voltage inversely proportional to the load.

According to a twenty-sixth aspect of the present invention, in the electric circuit, one end is connected to a voltage power supply and the other end is connected to one end of the strain-sensitive resistor. Voltage dividing resistor having a large resistance value, and the other end is connected to GND.
25. The floor presence detection according to claim 1, further comprising: the strain-sensitive resistor connected to a terminal; and an amplifier that amplifies a voltage applied between terminals of the strain-sensitive resistor and outputs the amplified voltage to the outside. Device.

Also in the present invention, the voltage applied between the terminals of the strain-sensitive resistor is “Vcc × r / (R + r)”. Here, if r≫R, “Vcc × r / (R + r)”
Can be approximated by “Vcc × R / r”. If R is proportional to the load, the amplifier outputs a voltage proportional to the load.

According to a twenty-seventh aspect of the present invention, on the lower surface of the sensor substrate, four strain-sensitive resistors are provided at 90 ° on the same circumference.
The electric circuit has an end connected to the voltage power supply and the other end connected to one end of the strain-sensitive resistor, and having a resistance value sufficiently larger than the resistance value between the terminals of the strain-sensitive resistor. Four voltage dividing circuits each including a pressure resistor and the strain-sensitive resistor having the other end connected to GND, and amplifying a voltage applied between the terminals of the strain-sensitive resistor provided for each of the voltage dividing circuits. 4
3. An amplifier comprising: one amplifier; and an adding circuit for adding output voltages of the four amplifier circuits.
4. The on-bed detection device according to 4.

The output voltage of the amplifier corresponding to each strain-sensitive resistor is proportional to the load applied to each strain-sensitive resistor. Therefore, if the sum of the loads applied to the four strain-sensitive resistors is the same as the load applied to the pressurized body, the output value of the adding circuit that adds the output voltages of the four amplifier circuits is proportional to the load applied to the pressurized body. .

According to a twenty-eighth aspect of the present invention, an electric circuit is provided on a sensor substrate, wherein the electric circuit is provided on a sensor substrate. Device.

In the bed detection device of the present invention, since the electric circuit is provided on the sensor substrate, the space for providing the electric circuit is small.

A further improvement of the above-mentioned invention.
The invention described in (1), wherein holes for leading input / output leads from the sensor case are provided on a plurality of side wall surfaces of the sensor case. There is a floor detection device.

In the occupancy detection device of the present invention, holes for leading input / output leads from the sensor case are provided on the plurality of side wall surfaces of the sensor case. High degree.

According to a thirty-second aspect of the present invention, a plurality of projections for pressing the sensor substrate are provided on the back surface of the pressing body, and the plurality of projections are provided on the upper surface of the pressing body. 30. The occupancy detection device according to claim 1, wherein a recess for placing a leg of the bedding is formed inside a polygon connecting a plurality of protrusions.

In the bed detection device of the present invention, since the concave portion for placing the legs of the bedding is formed inside the polygon connecting the projections on the upper surface of the pressing body, the center of the load connects the projections. Located inside the polygon. Therefore, in the occupancy detection device of the present invention, the bias error is small.

According to a thirty-first aspect of the present invention, the cover member is detachably attached to the sensor case, and the leg of the bedding is placed on a correct position on the upper surface of the pressing body. A concave portion is formed, the cover member is removed, the pressurizing body is replaced with another kind of pressurizing body, and then the cover member is attached, so that it can be applied to various kinds of bedding. The occupancy detection device according to any one of claims 1 to 30.

In the presence detection device of the present invention, the pressurized body can be replaced according to the shape of the bedding casters and the like. Therefore, the occupancy detection device of the present invention has high compatibility.

According to a thirty-second aspect of the present invention, there is provided a sensor case, wherein a plurality of fan-shaped, substantially triangular or substantially trapezoidal projections are provided on the same circumference at intervals. On the sensor substrate, a plurality of strain-sensitive resistors are arranged at intervals in the same circumference, and the sensor substrate is supported by the protrusions of the sensor case, and the pressure-sensitive resistor is connected to the protrusions. The occupancy detection device according to any one of claims 1 to 31, wherein the occupancy detection device is located between the devices.

In the bed detection device of the present invention, the sensor substrate is supported by the projection, and the intermediate portion supported by the projection is pressed. Therefore, the sensor board is in a state where the sensor board presses the middle part of the support beams at both ends. The sensor substrate is supported by a fan-shaped or substantially triangular or substantially trapezoidal projection, and the supported portion has a certain area. Therefore, the deformation of a specific section surrounded by the projection piece has little effect on other sections.

According to a thirty-third aspect of the present invention, the sensor case is provided with a plurality of projections, and the sensor substrate is supported by the projections. 33. The occupancy detection device according to claim 1, wherein a reinforcing layer is provided, and the strain-sensitive resistor is provided between contact portions with the protrusion. .

In the occupancy detection device of the present invention, a reinforcing layer is provided at a portion where the sensor substrate comes into contact with the projection. Therefore, the contact portion of the sensor substrate with the projection is less deformed, and the intermediate portion between the contact portions of the sensor substrate and the projection provided with the strain-sensitive resistor is deformed according to the load received from the bedding.

The invention according to claim 34 is a sensor case in which four projections are provided at 90 ° intervals on a concentric circumference substantially at the center of the inner bottom surface of the case opened upward, a metal base and the metal base. A substrate that is configured with an insulating glass layer covering the surface of the sensor case and is mounted on the protrusion of the sensor case,
The pressure-sensitive part is supported via a circular or polygonal ring-shaped pressure-sensitive part, and a connecting part provided on a straight line connecting the center of the ring of the pressure-sensitive part and the protrusion and on the outer peripheral side of the protrusion. The elasticity is such that four strain-sensitive resistors are attached at 90 ° intervals on the circumference of the ring on the lower surface of the pressure-sensitive portion so as to be located between two adjacent protrusions of the sensor case. A deformable sensor substrate, placed on the upper surface of the sensor substrate, and arranged at approximately the center of the lower surface so as to abut against the side surface of the sensor substrate opposite to the location where the strain-sensitive resistor is attached, A pressurizing body formed with a concave portion for placing one leg of the bedding substantially at the center of the upper surface, and a sensor case cover having an opening for exposing the upper surface of the pressurizing body and covering an upper surface opening of the sensor case; The strain sensing of the pressure sensing section of the sensor substrate Connecting the antibody and the circuit portion in the wiring conductors patterned so as not to contact the projection of the street the sensor case the lower surface of the connecting portion, the circuit portion,
A calculation for calculating and outputting the outputs of a voltage-dividing resistor composed of the same material as the strain-sensitive resistor of the pressure-sensitive portion, and four voltage-dividing circuits including the strain-sensitive resistor and the voltage-dividing resistor. This is an on-bed detection device provided with a circuit.

The present invention is an invention having substantially the same operation and effect as the above-mentioned invention of the thirteenth aspect. However, in the above-mentioned invention of the thirteenth aspect, the output according to the load is taken out by the differential amplifier circuit. On the other hand, according to the present invention, an output corresponding to the load is extracted by an arithmetic circuit.

[0076]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a first embodiment of the present invention. (Embodiment 1) FIG. 1 is a perspective view of an on-bed detection device according to a first embodiment of the present invention. FIG. 2 is an exploded perspective view of the occupancy detection device of FIG. FIG. 3 is a rear view of the pressurizing body employed in the bed detection device of FIG. FIG. 4 is an AA cross-sectional view of the pressurizing body employed in the bed detection device of FIG. FIG.
FIG. 2 is a plan view of a sensor case used in the bed detection device of FIG. 1. FIG. 6 is a sectional view of the sensor case of FIG. FIG. 7 is a schematic diagram of a sensor substrate employed in the bed detection device of FIG. FIG. 8 is a component layout diagram of the sensor board of FIG. FIG. 9 is a circuit diagram of the sensor substrate of FIG.
FIG. 10 is a plan view showing a state where the sensor substrate is mounted on the sensor case. FIG. 11 is a cross-sectional view showing a state where the sensor substrate is mounted on the sensor case. FIG.
It is a top view of an in-bed detection device. FIG. 13 is a sectional view of the occupancy detection device of FIG.

In each of the figures, reference numeral 1 denotes an on-bed detection device according to the first embodiment of the present invention. The on-bed detection device of the present embodiment includes a pressing body 2, a cover member 3, a sensor case 5, and a sensor substrate 6, as shown in FIG. Explaining one by one, the pressurizing body 2 is made by injection molding of a polypropylene resin, a polyethylene resin, an ABS resin, or the like, and has a substantially rectangular plate shape. A flange 10 is provided on the entire circumference of the pressure body 2. The area covered by the flange portion 10 is larger than the sensor substrate 6 described later. The flange portion 10 functions as an eave, as described later, in addition to the function of preventing the pressure body 2 from being detached. An arcuate concave portion 11 is provided on the upper surface of the pressing body 2. The arc-shaped concave portion 11 is configured such that a caster (not shown) mounted on the leg of the bedding (bed) is fitted and fixed, the bottom surface 9 has an arc shape, and the side surfaces 12 are both flat. It is. The pressure body 2 employed in this embodiment is for a so-called double caster, and has two arc-shaped concave portions 11 formed therein.

On the back surface of the pressing body 2, a grid 1 for reinforcement is provided.
3 are provided. In the center of the back surface of the pressure body 2, four projections 15 are provided. The arrangement of the protrusions 15 is such that the sides of the rectangle connecting the protrusions 15 are parallel to the sides of the pressing body 2. The center of the rectangle connecting the projections 15 coincides with the center of the load received from the bedding when the caster of the bedding (bed) is fitted and fixed in the arcuate concave portion 11 on the surface side. In other words, the arc-shaped concave portion 11 on the front surface side of the pressing body 2 is formed for placing the leg of the bedding on the inside (preferably the center) of the polygon connecting the projections 15 on the back surface of the pressing body 2. It is. In the vicinity of the outer periphery of the back surface of the pressure body 2, a wall portion (projection) 17 is provided downward over the entire periphery. The wall (projection) 17 covers the sensor substrate 6 as described later.

The cover member 3 is made of metal, is square as shown in FIG. 2, and has a square opening 20 at the center. The opening 20 of the cover member 3 is
The area is larger than the area of the upper part of the pressure body 2 and smaller than the area of the flange portion 10. The cover member 3 is provided with mounting holes 21 at four corners. FIG. 1 shows a state in which a seal is stuck to hide the mounting hole 21.

The sensor case 5 is made of polypropylene resin,
It is made by injection molding of polyethylene resin, ABS resin, or the like, or made of metal, and has a roughly box-like shape with an open top. A slope 25 is provided on one surface of the sensor case 5. A convex wall 26 is provided at the center of the portion where the slope 25 is formed. The convex wall 26 fits the gap between the wheels of the double caster. The direction of the caster of the bedding (bed) is regulated by the convex wall 26 and climbs the slope 25. The slope-down portion of the slope 25 is flat and has a fixing hole 27 for fixing the occupancy detection device 1 to the floor.

Most of the sensor case 5 forms a box having an open top as described above. That is, the sensor case 5 has a bottom surface 28, and walls 30abcd are erected on four surfaces continuous with the bottom surface 28.

Here, the shape of the bottom surface 28 of the sensor case 5 is special and will be described in detail. At the center of the sensor case 5, a projection 35 having a substantially circular shape in plan view is provided.
The projection 35 lacks a diagonal part with respect to the shape (square) of the central part and the box part of the sensor case 5.
Therefore, the projection 35 has four fan-shaped projection pieces 35.
abcd has a shape provided at 90 ° intervals on the same circumference.

The rib-shaped projections 40, 41, 42, 4 extend from the four walls 30abcd to the respective pieces 35abcd of the projections 35.
3 are provided. Further, the bottom surface 28 of the sensor case 5
Is provided with four projections 45 for mounting the sensor substrate. The sensor substrate mounting projections 45 are provided at positions corresponding to the corners of the square, and the center thereof coincides with the center of the projection 35 described above. Therefore, the inscribed circle of the sensor board mounting projection 45 is concentric with the circular shape of the central projection 35. In addition, four protrusions 50 having the same shape are provided. The protrusion 50 regulates the movement of the sensor substrate 6.

On the top surface of the sensor case 5, four screw holes 51 are provided. A notch 53 for leading out a lead wire is provided in the wall 30b on the surface facing the slope 25. Further, rectangular openings 52 are provided in the left and right walls 30ac. That is, in this embodiment, holes and cutouts are provided at a total of three places on the wall surface other than the wheel guiding slope 25 so that the input / output lead wires coming out of the sensor board 6 can be provided. The opening 52 is a spare hole for drawing out a lead wire, and is usually closed by a blind plate.

The sensor substrate 6 has a surface of a metal base material covered with an insulating glass layer, and a strain-sensitive resistor and a detection circuit are provided on the surface. The sensor substrate 6 has elasticity and flexes. Here, the metal base material needs to match the expansion coefficient with the insulating glass layer.
140 × 10 −7 / ° C. stainless steel is preferred. The insulating glass layer is made of non-alkali glass from the viewpoint of electrical insulation, heat resistance and bonding strength. Strain-sensitive resistor 32
Use a resistive material such as Cu-Ni alloy, Ni-Cr alloy, ruthenium oxide, etc., whose electric resistance changes due to various strain changes, and use a drawing method, a metal mask method, a doctor blade method, and offset printing. It is preferable to print and sinter by a printing method, a screen printing method or the like. That is, when stainless steel is used as the base material layer and insulating glass is selected as the insulating layer, the thermal expansion coefficients of the two materials are close to each other, so that no separation occurs during firing, and the integrity of the base material layer and the insulating layer is reduced. high. Further, when stainless steel and insulating glass are used, the state between them can be made close to a chemical bond. The electrodes at both ends of the strain-sensitive resistor are silver-platinum, silver-
It is desirable that the conductive paste is formed by printing a conductive paste such as palladium or gold, drying and firing.

The outer shape of the sensor substrate 6 is as shown in FIGS. 7 and 8, and the whole shape is a square plate. A circular opening 60 is provided at the center. An arc-shaped groove 62 is provided concentrically with the circle of the opening 60. The groove 62 is divided into four parts of abcd as shown in FIG. Therefore, the sensor substrate 6 is attached to the main body 65.
A circular ring-shaped peninsula portion 66 is formed at the center of the main body portion 65, and the main body portion 65 and the peninsula portion 66 are connected by a narrow connecting portion 67. At four corners of the sensor board 6, mounting holes 70 are provided. The arrangement of the holes 70 is square. In this embodiment, the main body portion 65
The peninsula part 66 functions as a pressure-sensitive part. A reinforcing layer made of epoxy resin is provided near the connecting portion 67 of the pressure-sensitive portion (the peninsula portion 66). The epoxy resin reinforcing layer 68 is provided at the hatched portion in FIG. 7, and is reinforced in a fan shape in plan view.

The sensor substrate 6 employed in this embodiment is provided with a circuit as shown in FIG. That is, in FIG. 9, R32a, R32b, R32c, and R32d are strain-sensitive resistors. Note that the pressure-sensitive resistors R32a and R32
The positional relationship between the sensor substrate 6 of b, R32c, and R32d and the physical positional relationship with other members are as shown in FIG. 10, and the strain-sensitive resistors R32a to R32d have the same circle at 90 ° intervals. The sides of the rectangle formed on the circumference and formed by connecting these with a straight line are perpendicular and parallel to the traveling direction of the caster regulated by the convex wall 26. Returning to the description of the circuit, r1, r2, r3, and r4 are first to fourth voltage-dividing resistors disposed in the circuit section and are made of the same material as the first to fourth strain-sensitive resistors R32a to R32d. In this embodiment, the voltage-dividing resistors r1, r2, and r constituting a bridge circuit in combination with the strain-sensitive resistors R32a to R32d.
Since r3 and r4 are made of the same material as the strain-sensitive resistors R32a to R32d, the temperature dependences of these resistance values substantially match, and there is no need for temperature correction.

The above-described first to fourth strain-sensitive resistors R32
a to R32d are arranged in series with first to fourth voltage dividing resistors r1 to r4, respectively, and they are connected in parallel as a set between a power supply and GND. Here, of each set of strain-sensitive resistors R32a to R32d, the first and third strain-sensitive resistors R32d and R32c are on the power supply side, and the second and fourth strain-sensitive resistors R32b and R32a are , GND side. Thus, the first to fourth voltage dividing circuits 1001,
1002, 1003 and 1004 are formed. The following circuits constitute a set of bridge circuits in the voltage dividing circuits 1001 and 1002. The voltage dividing circuit 100
3, 1004 also constitute a set of bridge circuits. Each bridge circuit includes two strain-sensitive resistors, which are combined at diagonal positions as shown in FIG.

R5 to r12 are circuit resistors for determining the amplification factor of the differential amplifier circuit, and are the first to fourth strain-sensitive resistors R32a to R32a to R12.
It is made of the same material as R32d. In the present embodiment, the circuit resistance for determining the amplification factor of the amplifier circuit is also made of the same material as the strain-sensitive resistors R32a to R32d, so that the strain-sensitive resistor of the pressure-sensitive section and the amplifier circuit of the circuit section are different. The dependence of the resistance value of the circuit resistor for determining the amplification factor on the temperature can be made substantially the same, and the variation in the output change characteristic with respect to weight is further reduced.

IC5 and IC6 are amplifiers, and 1007 is an addition circuit. IC5 and IC6 are the first on the inverting input side,
The outputs of the third voltage dividing circuits 1001 and 1003 are input via circuit resistances r5 and r7, respectively, and the circuit resistance r
9. Connected to the output by r11. Also, the outputs of the second and fourth voltage dividing circuits 1002 and 1004 are input to the non-inverting input side via circuit resistances r6 and r8, respectively, and connected to GND via circuit resistances r10 and r12.
First and second differential amplifier circuits 1005 and 1006 are formed. Although the details of the adder circuit 1007 are omitted, the outputs from the first and second differential amplifier circuits 1005 and 1006 are added by an adder circuit to form a voltage output Vout. The output voltage Vout is given by the following equation.

[0091]

(Equation 1)

Here, A ₁ is the amplification factor of the first and second differential amplifier circuits 1005 and 1006. That is, the load applied to the pressing body 2 can be measured by converting the amounts of change in the resistance values of the first to fourth strain-sensitive resistors R32a to R32d into a voltage and adding them.

[0093] The above circuit configurations are all the same as those of the sensor substrate 6.
Is provided on the back side. The position of each member is such that the strain-sensitive resistors R32a to R32d are provided in the pressure-sensitive portion (the peninsula portion 66) of the sensor substrate 6, and all other members are provided in the circuit portion (the main body portion 65). . That is, the strain-sensitive resistors R32a to R32d are arranged at 90 ° intervals in the middle portion of the pressure-sensitive portion (the peninsula portion 66) of the substrate 6 as shown in FIGS. The arrangement of other components is as shown in FIG. The signal line connecting them passes through the lower surface of the connection part 67 through the strain-sensitive resistors R32a to R32d of the pressure-sensitive part (the peninsula part 66) of the sensor substrate 6 and the circuit part (the main body part 65). It is connected by a conductor pattern wired so as not to contact the projection 50. Therefore, in this embodiment, there is no contact between the conductor and the protrusion 50 and the like, and there is no disconnection or short circuit of the conductor pattern. Further, according to this configuration, a lead wire for connecting the strain-sensitive resistors R32a to R32d to the detection circuit and the like becomes unnecessary, and not only is the cost reduced, but also
Erroneous detection due to noise can also be prevented.

Although the circuit employed in this embodiment is as described above, it is of course possible to obtain an output corresponding to the load of the bedding by using another circuit configuration. As a general guideline when designing a circuit for taking out an output corresponding to the load of the bedding, one end is connected to GND, the other end is connected to one end of the strain-sensitive resistor, and the resistance value between the terminals of the strain-sensitive resistor is determined. A voltage-dividing resistor having a sufficiently small resistance value, the strain-sensitive resistor having the other end connected to a voltage power supply, and an amplifier for amplifying a voltage applied between terminals of the voltage-dividing resistor and outputting the amplified voltage to the outside And a configuration having According to this circuit configuration, the voltage applied between the terminals of the voltage dividing resistor is
“Vcc × r / (R + r)”. Here, if r≪R, the voltage “Vcc × r / (R +
r) can be approximated by Vcc × r / R. If R is proportional to the load, the amplifier outputs a voltage inversely proportional to the load.

As another configuration, one end is connected to a voltage power supply and the other end is connected to one end of a strain-sensitive resistor, and has a resistance value sufficiently larger than a resistance value between terminals of the strain-sensitive resistor. It is also conceivable to adopt a configuration including a resistor, the strain-sensitive resistor having the other end connected to GND, and an amplifier that amplifies a voltage applied between terminals of the strain-sensitive resistor and outputs the amplified voltage to the outside. Also in this circuit configuration, the voltage applied between the terminals of the strain-sensitive resistor is “Vcc × r / (R + r)”.
Here, if r≫R, “Vcc × r / (R + r)”
Can be approximated by “Vcc × R / r”. If R is proportional to the load, a voltage proportional to the load is output from the amplifier.

Although the present embodiment employs a differential amplifier circuit, the output of the voltage dividing circuit can be calculated and output by a circuit having another configuration.

Next, an assembling structure of the occupancy detection device 1 of this embodiment will be described. In the occupancy detection device 1, the sensor case 5 is mounted with the surface on which the strain-sensitive resistors R32a to R32d and the amplifier circuit are provided facing downward. Specifically, the sensor board mounting projections 45 of the sensor case 5 are inserted into the mounting holes 70 at the four corners of the sensor board 6 for positioning. The arrangement of the mounting hole 70 and the sensor board mounting projection 45 is as follows.
Since both are square, the sensor substrate 6 can be arbitrarily attached at every 90 °. When the sensor substrate 6 is mounted on the sensor case 5, as shown in FIG.
Abuts on each piece of the central projection 35 of. Therefore, each of the strain-sensitive resistors R32a to R32d has a projection 3 at both ends.
5 is attached to the lower surface of the intermediate portion of the beam.

Then, the pressure body 2 is placed on the sensor case 5, and the cover member 3 is further mounted. Pressing body 2
The upper portion is exposed to the outside from the flange portion 10, and the other portions are covered by the cover member 3. Then, the four projections 15 on the back surface of the pressure body 2 are in contact with the back surfaces of the strain-sensitive resistors R32a to R32d of the sensor substrate 6, respectively. As described above, each of the strain-sensitive resistors R32a to R32d has a configuration in which both ends are attached to the lower surface of an intermediate portion of a beam supported by the protrusions 35, and the protrusions 15 of the pressing body 2 It comes into contact with the back side of the strain-sensitive resistors R32a to R32d. Therefore, the pressure-sensitive portion (the peninsula portion 66) of the sensor substrate 6
When the beam is viewed as a beam, both ends of the beam are supported by the projection 35 of the sensor case 5, and a concentrated load is applied to the beam by the projection 15 of the pressing body 2 in the middle. And the strain-sensitive resistor R
32a to 32d are provided.

The strain-sensitive resistors R32a to R32d are 9
The protrusions 15 of the pressurizing body 2 are also arranged on the same circumference at an interval of 90 °. The sides of the square formed by the connection are perpendicular and parallel to the traveling direction of the caster regulated by the convex wall 26.

As employed in the present embodiment, the configuration in which the sides of the rectangle formed by connecting the projections 15 of the pressing body 2 are perpendicular and parallel to the traveling direction of the caster is a diagonal as shown in FIG. Strain-sensitive resistors (R32a and R32c) (R32b and R3
2d) has an advantage that it can be detected by reducing the influence on the bias of the load in combination with the circuits constituting one bridge circuit, and is recommended. That is, contrary to the configuration of this embodiment, the center of the protrusion 15 of the pressing body 2 is connected diagonally, and one of the diagonals overlaps the traveling direction of the wheel, and the other is perpendicular to the traveling direction of the wheel. When the caster wheels are deviated right and left with respect to the traveling direction, the projections of the pressure body 2 are deviated in the deviated direction because the distorted resistor 32 is disposed at that position. A load is applied to only three points of the portion, and no load is applied to one point. Conversely, a load may be applied to only one point. As a result, the load cannot be accurately detected. On the other hand, as adopted in the present embodiment, if the square sides formed by connecting the projections 15 of the pressing body 2 are configured to be perpendicular and parallel to the traveling direction of the bedding casters, the wheels themselves Is pressed to the left or right with respect to the traveling direction,
Even if a large load is applied to the two places where the projections 15 are biased, the projections 15 of the pressurizing body 2 are formed to receive the load of the wheel on the four surfaces. Take it. The detection circuits are also R32a, R32c, R
Since the bridge circuit is formed by the diagonal difference between 32b and R32d, the influence on the bias of the load can be reduced and detected. The above-mentioned advantages are particularly remarkable in a case where a single type caster is mounted, such as the presence detection apparatus shown in FIG.

According to the present embodiment, the sensor substrate 6 is composed of a pressure-sensitive portion (a peninsula portion 66) to which a load is applied and a circuit portion (the main body portion 65), and the strain-sensitive resistor 32 is connected to the pressure-sensitive portion (the peninsula portion). Part 6
By arranging at 90 ° on the same circumference of 6), the weight applied to the pressing body 2 can be added to the strain-sensitive resistor 32 by dividing it into four parts. Therefore, the length, width, and thickness of the beam of the pressure-sensitive portion (the peninsula portion 66) can be designed according to the load of 1/4, so that the pressure-sensitive portion (the peninsula portion 66) can be reduced, and the detection circuit is also provided. It can be formed on the same substrate, and can be realized at low cost and space saving.

The operation of the occupancy detection device 1 configured as described above will be described below. Presence detection device 1
Is installed on the floor of a hospital or the like, on which a bedding caster is placed. In the occupancy detection device 1 of the present embodiment, since the slope 25 is provided in the sensor case 5, it is easy to guide the bedding, and it is easy to put the casters on the occupancy detection device 1. Further, in the presence detection device 1 of the present embodiment, since the convex wall 26 is provided at the center of the portion where the slope 25 is formed, the wheels of the double caster
Accordingly, the caster is guided and the caster is placed on the bed detection device 1.

In this embodiment, since the arc-shaped concave portion 11 is provided on the upper surface of the pressurizing body 2, when the caster is mounted on the bed detection device 1, the wheels of the caster are moved to the arc-shaped concave portion 1.
1 and the position of the caster is fixed to the center of the pressing body 2. That is, the caster is fixed to the inside of a rectangle that has four projections 15 provided on the back surface of the pressing body 2.
Then, the pressure body 2 is pressed by the caster, and the pressure-sensitive portion (the peninsula portion 6) of the sensor substrate 6 is pressed through the projection 15 of the pressure body 2.
6) is pressed. The pressure-sensitive part (the peninsula part 6) of the sensor substrate 6
6) are adjacent protruding pieces (35a, 35b) (35b,
Each section sandwiched by 35c) (35c, 35d) (35d, 35a) acts as if both ends support beams,
The portion bends. In addition, the protrusions of each sensor substrate 6 and 35
A reinforcement layer made of epoxy resin is provided at the part that contacts the abcd, and the part has little bending, so the bending of each section is difficult to propagate to the next section, and each section is formed by an independent support beam. The amount of deflection is approximated. As a result, each section of the sensor substrate 6 generates a distortion according to the load, the resistance value of the strain-sensitive resistors R32a to R32d becomes a value corresponding to the distortion of the sensor substrate 6, and a voltage corresponding thereto is output.

If a large load or an unbalanced load is applied to the pressing body 2 due to some influence and the pressing body 2 sinks greatly,
A wall (projection) 17 provided on the back surface of the pressure body 2 is provided with projections 40, 41, 42, 43 provided on the bottom surface of the sensor case 5.
And supports the pressurizing body 2. Therefore, the amount of depression of the pressure body 2 is limited, and the sensor substrate 6 is protected.

In particular, in the on-bed detection device 1 of this embodiment, since the slope 25 is provided so that the bedding can be easily installed on the pressurizing body 2, the pressurizing body 2 is excessively moved when placing the bedding. When trying to get over, the pressurizing body 2 tilts in the direction in which the user wants to get over. When the pressing body 2 tilts, an abnormal load is likely to be applied to the sensor substrate 6, but the wall (projection) 17 of the pressing body 2
Since the protrusion 41 of the sensor case 5 is provided at a position facing the sensor case 5, the abnormal load can be absorbed by the protrusion 41 of the sensor case 5 and can be prevented from being applied to the sensor substrate 6.

When the occupancy detection device 1 is used,
When the floor on which the occupancy detection device 1 is attached is cleaned, for example, when wiping or washing is performed, water or detergent water may be accidentally applied to the occupancy detection device 1. In this case, it is inevitable that some water enters the inside through the opening 20 of the cover member 3, but it is possible to prevent water or the like from directly hitting the sensor substrate 6. That is, in the bed detection device 1 of the present embodiment, the pressing body 2
Is provided around the sensor substrate 6, and the flange 10 serves as an eave and covers the sensor substrate 6. The wall portion (projection) 17 hangs down so as to surround the sensor substrate 6. That is, the main body portion of the pressure body 2 and the flange portion 10
The upper part of the sensor substrate 6 is covered by the above, and the wall (projection) 17 of the pressurizing body 2 hangs down so as to surround the sensor substrate 6, so that the sensor substrate 6 is not directly hit by water droplets or detergent liquid.

Next, a method of using the occupancy detection device of this embodiment will be described.

FIG. 14 is an explanatory diagram showing an example of use of the occupancy detection device of this embodiment. FIG. 15 is a characteristic diagram illustrating a relationship between the load applied to the bedding and the output voltage of the presence detector. In FIG. 14, reference numeral 80 denotes bedding for a hospital or the like, and the underbed detection device 1 of this embodiment is disposed on the lower surface of the leg. In this embodiment, the bedding 80 has four legs, and the occupancy detection device 1 is arranged below each leg. The signal of the occupancy detection device 1 is input to the control unit 81, and the control unit 81 determines the output of the occupancy detection device 1. The signal from the control unit 81 is further connected to a notification device 82 installed in a nurse room, central control room, or the like, which is located away from the occupant.

When the on-bed detection device 1 is attached to the four legs of the bedding 80, the weight of the bedding itself is a1 [kg], and the total output voltage of the on-bed detection device is V1 [V]. . Next, the weight when the patient goes to bed on the bedding 80 is a2 [k
g], the output voltage of the occupancy detection device becomes V2 [V]. Therefore, the weight a1 [kg] of the bedding 80 (output voltage V
1 [V]) and the determination level is a3 [kg] so that the weight of the patient sleeping on the bedding 80 is smaller than a2 (output voltage V2 [V]). V] (a1 <a3 <a2, V1 <V3 <
V2), the value of V3 [V] is stored in the control unit 8
1 is stored. And after confirming that the patient went to bed,
The occupancy detection device 1 is operated, and if the patient leaves the bed at night, the output of the occupancy detection device becomes the judgment level (V3 [V]).
Since it becomes the following, via the control unit 81,
A signal is sent to a notification device 82 installed in a nurse's room, a central control room, or the like, which is located away from the occupant to be notified. As described above, the occupancy detection device according to the present embodiment can check the occupancy status without going directly to the patient's room and can respond quickly to the patient. Therefore, the mental and physical burden on the caregiver and the nurse can be reduced.

In the above example, the total load applied to the occupancy detection device 1 is output to judge only whether or not a patient is present. However, the occupancy detection device 1 provided on the four legs is determined. Analyze the output of the bedding and detect the center of gravity and distribution of the load on the bedding,
It is also possible to know the posture of the patient or the like. According to such a configuration, it is possible to know from a remote position, for example, a state in which the patient has turned over or is sitting on the edge. In order to know such a patient's posture, bedding 8
It is more desirable to mount as many bed detection devices 1 as possible at 0, but empirically, if the bed detection devices 1 are provided on both the legs of the bedding 80 on the patient's head side, there is no practical problem. It is possible to know the posture of the patient or the like with a degree of accuracy that is not so high.
Even if only one leg presence detection device 1 is provided, if the weight of the patient is known, the posture of the patient or the like can be known with an accuracy that is practically acceptable.

In the example of use described above, the bed detection devices 1 are arranged below the legs of the bedding 80, for example.
Even if the on-bed detection device 1 is arranged only under one leg, the on-bed detection can be performed. Hereinafter, this configuration will be described. FIG.
FIG. 9 is an explanatory diagram showing another example of use of the occupancy detection device of the present embodiment. FIG. 17 is a characteristic diagram showing the relationship between the load applied to the bedding and the output voltage of the occupancy detection device.

In FIG. 16, the same parts as those in FIG. 14 are denoted by the same reference numerals, and the detailed description is omitted. The difference from the previous use example is that a stand 85 for adjusting the height of the bedding 80 to the point where only one occupancy detection device 1 is attached is provided.
Is provided. The operation of the occupancy detection device 1 configured as described above will be described below with reference to FIG. First, when the bed detection device 1 is attached to one leg of the bedding 80, the weight of the bedding 80 is a1 '[kg] and the output voltage of the bed detection device is V1' [V]. Next, considering the weight when the patient goes to the A, B, and C zones on the bedding 80, in the A zone, the weight of the patient is easily transmitted to the two legs of the bedding 80 on the bed detection device 1 side. So a2 '
[Kg], V2a '[V], and the relationship between weight and output voltage is A. Next, in the zone B, since the weight of the patient is equally divided into the four legs of the bedding 80, a2 '
[Kg] is V2b '[V], and the relationship between weight and output voltage is B. Further, in the C zone, since the weight of the patient mainly hangs on the two legs of the bedding 80 opposite to the bed detection device 1 side, a2 '[kg] becomes V2c' [V], and the relationship between the weight and the output voltage is obtained. Becomes C. In consideration of the fact that the output level is lowest when the patient is in the C zone, the determination level is set to a3 '[kg] and the output voltage of the in-bed detection device is set to V3' [V]. And the specified V3 '
[V] is stored in the control unit 81, and after confirming that the patient has gone to bed, the occupancy detection device 1 is operated. When the patient leaves the bed at night or the like, the output of the bed detection device 1 becomes equal to or lower than the determination level (V3 '[V]). A signal is sent to the notification device 14 installed in the central control room or the like to be notified. According to the above usage method, the presence detection can be performed by using only one presence detection device, and a more inexpensive presence detection device can be realized.

(Embodiment 2) Next, another embodiment of the present invention will be described. In each of the embodiments described below, the configuration of the above-described embodiment is partially omitted or partially replaced, and the configuration of a portion that is not particularly described is the same as that of the previous embodiment. is there. FIG. 18 shows a second embodiment of the present invention.
It is sectional drawing of the occupancy detection apparatus of an Example of FIG. The first mentioned above
In the occupancy detection device 1 of the second embodiment, the slope 25 is provided so that the caster can easily move. However, the occupancy detection device 100 of the second embodiment shows an example in which this is omitted. is there. Further, in the bed detection device 100 of the second embodiment, the flange portion 10 of the pressure member 2, the projection 17, and the like are also omitted.

(Embodiment 3) FIG. 19 is a sectional view of an on-bed detection device according to a third embodiment of the present invention. The occupancy detection device 101 according to the third embodiment differs from the occupancy detection device 101 in the position and the like of the strain-sensitive resistor 32 of the sensor substrate 6. The laminated structure of the sensor substrate 6 is the same as that of the previous embodiment. Both surfaces of the metal substrate 90 are covered with the insulating glass layer 91, and the strain-sensitive resistor 3
2 is provided. Reference numeral 93 denotes an electrode body that transmits an electric signal of the strain-sensitive resistor 32 formed on the insulating glass layer 91. A signal detection circuit 95 is formed on the insulating glass layer 91. In the occupancy detection device 101 of this embodiment, the strain-sensitive resistors 32 are more linearly arranged.

(Embodiment 4) FIG. 20 is a plan view of an on-bed detection device according to a fourth embodiment of the present invention. The first embodiment described above is applied to bedding having a so-called double caster, but the on-bed detection device 103 of the present embodiment is applied to single-caster bedding. That is, in the above embodiment, two rows of arcuate concave portions 11 are provided at the center of the pressing body 2.
Is provided, the on-bed detection device 1 of the present embodiment is provided.
In 03, only one arc-shaped concave portion 11 is provided at the center. In this embodiment, the slope 25 has no convex wall. In addition, the cover member 3 of the first embodiment described above is removed by loosening the screw, and the pressing member having the arcuate concave portion 11 for mounting the leg of the bedding in a correct position corresponding to the caster of the bedding is formed. After the replacement, by attaching the cover member 3, parts such as the sensor cover 5 and the like can be shared to be applicable to various kinds of bedding.

(Embodiment 5) FIG. 21 is a plan view of an on-bed detection device according to a fifth embodiment of the present invention. The on-bed detection device 105 of this embodiment is a slightly modified embodiment of the fourth embodiment, and a groove 98 for guiding a caster is provided at the center of the slope 25.
Is provided. The groove 98 has a wide lower surface and becomes narrower as approaching the pressure body 2.

(Embodiment 6) FIG. 22 is a sectional view of an on-bed detection device according to a sixth embodiment of the present invention. The on-bed detection device 106 of this embodiment has a structure in which the pressing body 2 has a double structure, the back surface (intermediate surface) 97 of the projection 15 is a spherical surface, and a wheel base 99 on which wheels are further mounted is provided thereon. . In the bed detection device 106 of the present embodiment, the load applied from the wheel of the bedding placed on the wheel base 99 is transmitted to the strain-sensitive resistor 32 via the wheel base 99, the pressing body 2, and the sensor substrate 6. Then, a change in the resistance value of the strain-sensitive resistor 32 is detected by a detection circuit (not shown). The on-bed detection device 106 of this embodiment includes the pressure body 2 having a spherical surface and a wheel base 99 on which wheels are mounted.
Even the zero wheel can be matched, and the restriction on the wheel fixed position can be eliminated, and the error due to the fixed position can be reduced.

In the configuration described above, the strain-sensitive resistor R32
a to R32d are arranged on the same circumference of the sensor substrate 6 at intervals of 90 °. In addition, the projection 15 of the pressure body 2 that presses the sensor substrate 6 and the projection 35abcd of the sensor case 5 that supports the sensor substrate 6 also have the strain-sensitive resistor R32a.
R32d, they were arranged on the same circumference at 90 ° intervals. Here, these are the diameters of the circles in which they are arranged. In general, the larger the diameter, the smaller the deviation error, the greater the amount of deformation of the sensor substrate 6, and the higher the detection accuracy. However, if the diameter increases, the outer shape of the occupancy detection device inevitably increases. Therefore, the size of the diameter is determined in consideration of the balance between the detection accuracy and the size of the outer shape.

In each of the embodiments described above, the projection 35 is provided on the bottom surface 28 of the sensor case 5 and the sensor substrate 6
Although the configuration for supporting the sensor substrate 6 in a hollow state has been disclosed, it is also possible to provide a concave portion such as a groove, arrange the mounting portion of the strain-sensitive resistor over the groove, and support the sensor substrate 6 in a hollow state. is there.

[0120]

As described above, the present invention detects the presence / absence of the patient's bedding by detecting the change in weight applied to the bedding by the distortion of the sensor substrate due to the load applied via the pressing body.
Therefore, it is possible to check the patient's in-bed status without directly visiting the patient, and to respond quickly to the patient. Further, it is possible to realize a bed detection device that can reduce the mental and physical burden on a caregiver and a nurse. In addition, in the occupancy detection device of the present invention, whether or not occupancy is detected is determined by the strain-sensitive resistor, so that the signal processing circuit can be simplified and the number of movable parts is small, so that there is an effect that failure is reduced. .

In the bed detection device of the present invention, since at least a part of the sensor substrate is supported in a hollow state, distortion is large,
High detection accuracy.

In the occupancy detection device of the present invention, since the concentrated load is applied by the projection, the amount of deformation of the sensor substrate is large, and the detection accuracy is high.

In the presence detection device of the present invention, since the strain-sensitive resistor is provided on the lower surface of the sensor substrate, and the upper surface of the sensor substrate is pressed by the projection, the detection accuracy of whether or not a person is present is high.

In the presence detection device of the present invention, when an uneven load is applied to the pressurized body, the direction of the load and the like are detected.
Further, in the floor presence detection device of the present invention, since the strain-sensitive resistors are arranged at 90 ° intervals on the same circumference on the sensor substrate, the weight applied to the pressing body is divided into four by the strain-sensitive resistors. The load can be detected by the link structure, and the detection accuracy is high.

Further, in the bed detection device of the present invention, since the sensor substrate is formed of an elastic body, the amount of deformation of the sensor substrate is large and the detection accuracy is high. Also, except for the load,
It returns to its original state and has high repeatability.

Further, in the bed detection device of the present invention, a combination of a metal substrate and an insulating glass layer is selected as a material for the sensor substrate, so that when the circuit or the like is provided, when the substrate is heated, Peeling does not easily occur, and the integration between the base material layer and the insulating layer is high. Therefore, the distortion of the sensor substrate is easily transmitted to the strain-sensitive resistor, and the detection accuracy is high.

Further, in the above invention, the sensor substrate is
It has a peninsula-shaped pressure-sensitive part that is narrower than the main body and the main body,
Since the strain-sensitive resistor is provided in the peninsula-shaped pressure-sensitive portion, the pressure-sensitive portion is easily deformed, and the detection accuracy is high. Further, since the pressure-sensitive portion is connected to the main body at the constriction, the main body is less affected by the deformation of the pressure-sensitive portion.

In the present invention, the pressure-sensitive portion is supported via the connecting portion disposed on the straight line connecting the center of the pressure-sensitive portion and the projection of the sensor case and on the outer peripheral side of the projection. The bending moment applied to the connection is small.

Further, in the occupancy detection device of the present invention, since the voltage-dividing resistor made of the same material as the strain-sensitive resistor is provided, the temperature dependence of the resistance value of the strain-sensitive resistor and the voltage-dividing resistor is provided. Are substantially the same, and there is no need for temperature correction.

Furthermore, since the presence detection device of the present invention has a cover member and the sensor case is covered with the cover member, dust does not enter the sensor case and erroneous operation and the like are reduced.

Further, in the bed detection device of the present invention, the pressurizing body covers the upper side of the sensor substrate and has a wall hanging down from the lower surface of the pressurizing body so as to surround the sensor substrate.
Water droplets, detergent liquid, and the like can be prevented from directly hitting the sensor substrate, and a highly reliable bed detection device can be realized.

Further, according to the present invention, when an excessive force is applied to the pressing body, a part of the pressing body comes into contact with a projection provided below the pressing body of the sensor case, and an excessive force is applied to the sensor substrate. Is added. Also, when a certain amount of load or uneven load is applied to the pressing body, the projection provided on the lower surface of the pressing body contacts a part of the sensor case, preventing excessive force from being applied to the sensor substrate. I do.

In the presence detection device according to the present invention, since the sides of the rectangle formed by connecting the centers of the projections of the pressurizing body are perpendicular and parallel to the traveling direction of the wheel, the load applied to the strain-sensitive resistor can be reduced. All bias error can be reduced. In addition to this, in the present invention, four strain-sensitive resistors are provided, and the detection circuit for detecting a change in the resistance value of the strain-sensitive resistor has two sets of bridge circuits, and is provided at diagonal positions. Since a circuit configuration is adopted in which a strain-sensitive resistor pressed by a certain projection is incorporated into a bridge circuit as a set,
The influence of the bias value is electrically complemented, and the bias error can be reduced.

Further, according to the present invention, the provision of the wheel guiding slope in the sensor case facilitates the guidance of the bedding.

Furthermore, in the floor presence detection device of the present invention, the sensor case is provided with a groove or a mountain serving as a wheel guide on the wheel guiding slope, so that the wheel is regulated and can be easily guided to the pressurized body and installed. A floor detection device can be realized.

Further, in the bed detection device of the present invention, a spherical portion is provided on the pressurizing member, and a platform is provided in contact with the spherical surface, and a part of the bedding is placed on the platform. It can be adjusted to the wheels of all kinds of bedding, the restriction of the wheel fixing position can be eliminated, and the error due to the fixing position can be reduced.

In the floor presence detection device of the present invention, the mounting holes provided in the sensor substrate and the projections of the sensor case inserted into the mounting holes are arranged at equal intervals on the same circumference. The mounting efficiency of the detection device can be increased.

[0138] In the presence detection apparatus of the present invention, an electric signal can be output as a voltage change, so that the structure of the incidental equipment is simple.

In the present invention, whether or not a bed is occupied can be detected by a voltage change that is directly proportional or a voltage change that is inversely proportional.

Further, in the bed detection device of the present invention, since the electric circuit is provided on the sensor substrate, not only is the structure simple, but the electric circuit does not require much space for installation.

Further, in the present invention, the holes for taking out the input / output lead wires are provided on the plurality of side wall surfaces of the sensor case, so that the degree of freedom in the lead wire drawing direction is high.

Further, according to the present invention, a plurality of projections for pressing the sensor substrate are provided on the back surface of the pressing body, and the legs of the bedding are provided on the upper surface of the pressing body inside a polygon connecting the plurality of projections. Since the recess for placing the bedding is formed, the load of the bedding is always inside the polygon connecting the protrusions, and there is little deviation error.

According to the present invention, since the pressure member can be replaced by removing the cover member, the interchangeability of parts is high.

Further, according to the present invention, since the sensor case is provided with a fan-shaped projection or the like and the sensor substrate is supported by the projection, the sensor substrate is stabilized and the detection accuracy is high.

Further, in the present invention, since the reinforcing layer is provided on the supporting portion, the deformation of the sensor base material is difficult to propagate to other sections beyond the supporting portion, and the detection accuracy is high.

[Brief description of the drawings]

FIG. 1 is a perspective view of an on-bed detection device according to a first embodiment of the present invention.

FIG. 2 is an exploded perspective view of the occupancy detection device of FIG. 1;

FIG. 3 is a back view of a pressurizing body employed in the bed detection device of FIG. 1;

FIG. 4 is an AA diagram of a pressurized body employed in the bed detection device of FIG. 2;
Sectional view

FIG. 5 is a plan view of a sensor case employed in the bed detection device of FIG. 1;

FIG. 6 is a sectional view of the sensor case of FIG. 5;

FIG. 7 is a schematic diagram of a sensor substrate used in the on-bed detection device of FIG. 1;

FIG. 8 is a component layout diagram of the sensor board of FIG. 7;

FIG. 9 is a circuit diagram of the sensor substrate of FIG. 7;

FIG. 10 is a plan view showing a state where the sensor substrate is mounted on the sensor case.

FIG. 11 is a sectional view showing a state in which a sensor board is mounted on a sensor case.

FIG. 12 is a plan view of the occupancy detection device of FIG. 1;

FIG. 13 is a sectional view of the occupancy detection device of FIG. 1;

FIG. 14 is an explanatory diagram illustrating an example of use of the occupancy detection device of the present embodiment.

FIG. 15 is a characteristic diagram showing a relationship between a load applied to the bedding and an output voltage of the bed detection device.

FIG. 16 is an explanatory diagram showing another example of use of the presence detection device of the present embodiment.

FIG. 17 is a characteristic diagram illustrating a relationship between a load applied to the bedding and an output voltage of the bed detection device.

FIG. 18 is a sectional view of an on-bed detection device according to a second embodiment of the present invention;

FIG. 19 is a sectional view of an on-bed detection device according to a third embodiment of the present invention;

FIG. 20 is a plan view of an on-bed detection device according to a fourth embodiment of the present invention.

FIG. 21 is a plan view of an on-bed detection device according to a fifth embodiment of the present invention.

FIG. 22 is a sectional view of an on-bed detection device according to a sixth embodiment of the present invention;

FIG. 23 is a configuration diagram showing an overall system of a conventional occupancy detection device.

FIG. 24 is a sectional view of an on-bed detection device incorporated in bedding.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 On-bed detection device 2 Pressurizing body 3 Cover member 10 Flange part 11 Arc-shaped concave part 15 Projection 17 Wall (projection) 25 Slope 26 Convex wall 28 Bottom surface 35 Projection 35abcd Projection piece 40, 41, 42, 43 Projection 45 Sensor board mounting Projection 52 Opening 53 Notch 62 Arc-shaped groove 65 Circuit part (body part) 66 Pressure sensitive part (peninsula part) 68 Reinforcement layer 68 100 Floor detection device 101 Floor detection device 103 Floor detection device 105 Floor detection Apparatus 106 Presence detection device 1001, 1002, 1003, 1004 Voltage divider circuit

 ──────────────────────────────────────────────────続 き Continuation of the front page (72) Kunihiko Ueda 4-5-2-5 Takaida Hondori, Higashi-Osaka City, Osaka Inside Matsushita Refrigerating Machinery Co., Ltd. (72) Yoshikatsu Inoue 4-Chome Takaida Hondori, Higashi-Osaka City, Osaka No. 2 Matsushita Refrigeration Co., Ltd. (72) Inventor Asahi Yasuda 4-5-2 Takaida Hondori, Higashi Osaka City, Osaka Pref.

Claims (34)

[Claims] A pressure body for receiving a load of the bedding, a sensor substrate provided with a strain-sensitive resistor on at least one surface and pressed by the pressure body, a sensor case for supporting the sensor substrate, An on-bed detection device, comprising: an electric circuit that outputs an electric signal according to a resistance value between terminals of the strain-sensitive resistor to the outside. 2. The on-bed detection device according to claim 1, wherein the sensor case includes a plurality of protrusions or one or more recesses, and supports at least a part of the sensor substrate in a hollow state. 3. The pressing body is provided with a projection, and the projection presses the sensor substrate.
Or the occupancy detection device according to 2. 4. The strain-sensitive resistor is provided on the lower surface of the sensor substrate, and the projection of the pressing body presses the upper surface of the sensor substrate and the upper portion of the strain-sensitive resistor. 4. The occupancy detection device according to any one of 1 to 3. 5. A plurality of strain-sensitive resistors are arranged on the sensor substrate at the same circumferential interval, and a projection or a strain-sensitive resistor supporting between the strain-sensitive resistors is provided on the sensor case. 5. The occupancy detection device according to claim 1, wherein a concave portion forming a space is provided in a mounting portion of the device. 6. A first, a second, a third, and a fourth strain-sensitive resistor are disposed on the lower surface of the sensor substrate on the same circumference. °, a fourth voltage dividing resistor having one end connected to GND and the other end connected to one end of the fourth strain-sensitive resistor, and the other end connected to a voltage power supply. A first voltage-dividing circuit comprising the fourth strain-sensitive resistor and a third voltage-dividing circuit having one end connected to a voltage power supply and the other end connected to one end of the second strain-sensitive resistor. A second voltage-dividing circuit including a resistor and the second strain-sensitive resistor having the other end connected to GND; a second voltage-dividing circuit having one end connected to GND and the other end connected to one end of the third strain-sensitive resistor; A third voltage-dividing circuit including a second voltage-dividing resistor connected to the second voltage-dividing resistor and the third strain-sensitive resistor having the other end connected to a voltage power supply; A first voltage dividing resistor having its one end connected to one end of the first strain sensitive resistor, the other end GN
A fourth voltage-dividing circuit including the first strain-sensitive resistor connected to D; and a terminal of the fourth voltage-dividing resistor based on a voltage value applied between terminals of the second strain-sensitive resistor. A first differential amplifier circuit that outputs a voltage value proportional to a voltage value obtained by subtracting a voltage value applied between the first differential amplifier circuit and the second voltage dividing resistor from a voltage value applied between terminals of the first strain-sensitive resistor A second differential amplifier circuit that outputs a voltage value proportional to a voltage value obtained by subtracting a voltage value applied between terminals of the amplifier, an output voltage value of the first differential amplifier circuit, and the second differential amplifier The occupancy detection device according to claim 1, further comprising an addition circuit that adds an output voltage value of the circuit. 7. The on-bed detection device according to claim 1, wherein the sensor substrate is made of an elastic body. 8. A sensor substrate, comprising: a metal base; and an insulating glass layer provided on the metal base, and an electrode for transmitting a signal to the strain-sensitive resistor on the insulating glass layer. 8. The occupancy detection device according to claim 1, further comprising a detection circuit configured to detect a change in resistance between the body and the strain-sensitive resistor. 9. The sensor substrate has a main body portion and a peninsula-shaped pressure-sensitive portion having a width smaller than that of the main body portion, and both are connected by a constriction portion, and the pressure-sensitive portion is provided with a strain-sensitive resistor. The occupancy detection device according to any one of claims 1 to 8, wherein the strain-sensitive resistor is wired to the main body through a narrowed portion. 10. The projections of the sensor case are provided at equal intervals on the circumference, and the sensor substrate has a base material layer and an insulating layer and is a substrate mounted on the projections of the sensor case. , A circular or polygonal ring-shaped pressure-sensitive portion, wherein the pressure-sensitive portion is a connecting portion disposed on a straight line connecting the center of the pressure-sensitive portion and the protrusion and disposed on the outer peripheral side of the protrusion. Four strain-sensitive resistors are disposed at 90 ° intervals on the lower surface of the pressure-sensitive portion and on the circumference of the ring, and the two strain-sensitive resistors are disposed adjacent to each other on the sensor case. The occupancy detection device according to claim 1, wherein the detection device is located between the protrusions. 11. The electric circuit according to claim 1, wherein the electric circuit has a voltage dividing resistor, and the voltage dividing resistor is made of the same material as the strain-sensitive resistor. Bed detection device. 12. A cover member provided with an opening at a part thereof and covering an upper surface of the sensor case, a part of the pressure body is exposed to the outside from the cover member, and the other part is covered by the cover member. The presence detection device according to any one of claims 1 to 11, wherein 13. A sensor case in which four projections are provided at 90 ° intervals on a concentric circle substantially at the center of the inner bottom surface of the case opened upward, a metal base and an insulating glass layer covering the surface of the metal base. A substrate mounted on the protrusions of the sensor case and configured as a circle or polygonal ring-shaped pressure-sensitive portion,
A circuit section that supports the pressure-sensitive section via a connecting section disposed on a straight line connecting the center of the ring of the pressure-sensitive section and the projection and on the outer peripheral side of the projection; An elastically deformable sensor substrate having four strain-sensitive resistors attached to the circumference of the ring at 90 ° intervals so as to be located between two adjacent protrusions of the sensor case; and an upper surface of the sensor substrate. It is placed, and four projections are arranged at approximately the center of the lower surface so as to abut on the side of the sensor substrate opposite to where the strain-sensitive resistor is attached, and one leg of the bedding is placed approximately at the center of the upper surface. A pressure body having a concave portion, and a sensor case cover having an opening for exposing an upper surface of the pressure body and covering an upper surface opening of the sensor case, wherein the strain-sensitive portion of the pressure-sensitive portion of the sensor substrate is provided. Connecting the resistor and the circuit unit to the connection unit The circuit portion is connected by a conductor pattern wired so as not to contact the protrusion of the sensor case through the lower surface, and the circuit portion includes a voltage-dividing resistor formed of the same material as the strain-sensitive resistor of the pressure-sensitive portion. A fourth voltage-dividing resistor having one end connected to GND and the other end connected to one end of the fourth strain-sensitive resistor, and the fourth circuit having the other end connected to a voltage power supply. A first voltage-dividing circuit including a fourth strain-sensitive resistor; a third voltage-dividing resistor having one end connected to a voltage power supply and the other end connected to one end of the second strain-sensitive resistor; A second voltage dividing circuit including the second strain-sensitive resistor having the other end connected to GND; and a second voltage-dividing circuit having one end connected to GND and the other end connected to one end of the third strain-sensitive resistor. A third voltage-dividing circuit including a second voltage-dividing resistor and the third strain-sensitive resistor having the other end connected to a voltage power supply; A first voltage dividing resistors having one end the other end is connected to a voltage source connected to one end of the first strain sensitive resistor, the other end GN
A fourth voltage-dividing circuit including the first strain-sensitive resistor connected to D; and a terminal of the fourth voltage-dividing resistor based on a voltage value applied between terminals of the second strain-sensitive resistor. A first differential amplifier circuit that outputs a voltage value proportional to a voltage value obtained by subtracting a voltage value applied between the first and second resistors; A second differential amplifier circuit that outputs a voltage value proportional to a voltage value obtained by subtracting a voltage value applied between terminals of the amplifier, an output voltage value of the first differential amplifier circuit, and the second differential amplifier An occupancy detection device, comprising: an addition circuit that adds an output voltage value of the circuit. 14. The pressure body covers an upper portion of the sensor substrate, and has a wall hanging below the sensor substrate so as to surround the sensor substrate.
The occupancy detection device according to any one of the above. 15. A projection is provided at a lower portion of the pressing body of the sensor case, and when a load equal to or more than a certain value or an uneven load is applied to the pressing body, a part of the pressing body contacts the projection. The occupancy detection device according to any one of claims 1 to 14, which is in contact with the occupancy detection device. 16. A projection is provided on a lower surface of the pressing body, and the projection comes into contact with a part of the sensor case when a load equal to or more than a predetermined value or an uneven load is applied to the pressing body. 16. The occupancy detection device according to any one of 1 to 15. 17. The bedding is linearly guided from one side of the pressing body to the other side, and the pressing body has four projections, and a rectangular side formed by cutting off the center of the projections. The sensor substrate is provided with four strain-sensitive resistors at positions corresponding to the four protrusions of the pressing body, which are perpendicular or parallel to the guiding direction of the bedding. The detection circuit for detection has two sets of bridge circuits, and a set of strain-sensitive resistors pressed by diagonally located protrusions is incorporated in the bridge circuit as a set. Item 17. The occupancy detection device according to any one of Items 1 to 16. 18. The on-bed detection device according to claim 1, wherein a wheel guiding slope is provided in the sensor case. 19. The floor presence detection device according to claim 1, wherein a groove or a mountain serving as a wheel guide is provided on a wheel guiding slope of the sensor case. 20. The pressing body according to claim 1, wherein the pressing body has a spherical portion, a base in contact with the spherical portion is provided, and a part of the bedding is placed on the base. 20. The occupancy detection device according to any one of 19. 21. The sensor device according to claim 1, wherein the mounting holes provided in the sensor substrate and the projections of the sensor case inserted into the mounting holes are arranged at equal intervals on the same circumference. An apparatus for detecting the presence of a child in a crab. 22. The bedding is a bed having four or more legs, and the presence detection device according to claim 1 is disposed between the legs and the floor. An on-bed detection device characterized by the above-mentioned. 23. The bedding is a bed having four or more legs, and the bed detection device according to any one of claims 1 to 21 is arranged between one leg and the floor. An on-bed detection device characterized in that: 24. The on-bed detection device according to claim 1, wherein the electric signal is a voltage corresponding to a resistance value between terminals of the strain-sensitive resistor. 25. A voltage dividing resistor having one end connected to GND and the other end connected to one end of a strain-sensitive resistor, and having a resistance value sufficiently smaller than a resistance value between terminals of the strain-sensitive resistor. 2. The apparatus according to claim 1, further comprising: a resistor, the strain-sensitive resistor having the other end connected to a voltage power supply, and an amplifier for amplifying a voltage applied between terminals of the voltage dividing resistor and outputting the amplified voltage to the outside. 25. The occupancy detection device according to any one of Items 1 to 24. 26. An electric circuit for voltage division having one end connected to a voltage power supply and the other end connected to one end of a strain-sensitive resistor and having a resistance value sufficiently larger than a resistance value between terminals of the strain-sensitive resistor. 2. The semiconductor device according to claim 1, further comprising a resistor, the strain-sensitive resistor having the other end connected to GND, and an amplifier for amplifying a voltage applied between terminals of the strain-sensitive resistor and outputting the amplified voltage to the outside. 25. The occupancy detection device according to any one of Items 1 to 24. 27. On the lower surface of the sensor substrate, four strain-sensitive resistors are arranged at 90 ° intervals on the same circumference, and one end of the electric circuit is connected to a voltage power supply and the other end is a strain-sensitive resistor. And a voltage-dividing resistor having a resistance value sufficiently larger than the resistance value between the terminals of the strain-sensitive resistor connected to one end of the resistor, and the strain-sensitive resistor having the other end connected to GND. A voltage circuit; four amplifiers provided for each of the voltage dividing circuits for amplifying a voltage applied between terminals of the strain-sensitive resistor; and an adding circuit for adding output voltages of the four amplifier circuits. The occupancy detection device according to any one of claims 1 to 24. 28. The occupancy detection device according to claim 1, wherein the electric circuit is provided on a sensor substrate. 29. The floor occupancy according to claim 1, wherein holes for leading input / output leads from the sensor case are provided on a plurality of side wall surfaces of the sensor case. Detection device. 30. A plurality of projections for pressing the sensor substrate are provided on the back surface of the pressing body, and on the upper surface of the pressing body,
2. A concave portion for placing legs of bedding is formed inside a polygon connecting the plurality of protrusions.
30. The occupancy detection device according to any one of claims 29 to 29. 31. A cover member is detachably attached to the sensor case, and a concave portion is formed on an upper surface of the pressurizing body for placing a leg of the bedding at a correct position, and the cover member is removed. 31. The storage device according to claim 1, wherein the cover member is attached after replacing the pressurizing body with another type of pressurizing body, so that the pressurizing body can be applied to various kinds of bedding. Floor detection device. 32. A plurality of fan-shaped, substantially triangular, or substantially trapezoidal projections are provided on the sensor case at intervals on the same circumference, and a plurality of strain-sensitive resistors are provided on the sensor substrate in the same circle. 32. The sensor board according to claim 1, wherein the sensor substrate is supported by the protrusions of the sensor case, and the pressure-sensitive resistor is located between the protrusions. The occupancy detection device according to any one of the above. 33. A plurality of projections are provided on the sensor case, the sensor substrate is supported by the projections, the sensor substrate has a reinforcing layer at a contact portion with the projections, and the strain-sensitive resistor is The occupancy detection device according to any one of claims 1 to 32, wherein the occupancy detection device is provided between contact portions with the protrusion. 34. A sensor case in which four projections are provided at 90 ° intervals on a concentric circumference substantially at the center of the inner bottom surface of the case opened upward, a metal base and an insulating glass layer covering the surface of the metal base. A substrate mounted on the protrusions of the sensor case and configured as a circle or polygonal ring-shaped pressure-sensitive portion,
A circuit portion that supports the pressure-sensitive portion via a connecting portion provided on a straight line connecting the center of the ring of the pressure-sensitive portion and the projection and on the outer peripheral side of the projection; and a lower surface of the pressure-sensitive portion. An elastically deformable sensor substrate having four strain-sensitive resistors attached to the circumference of the ring at 90 ° intervals so as to be located between two adjacent protrusions of the sensor case; and an upper surface of the sensor substrate. A recessed portion which is placed, and approximately four centers at the lower surface thereof are arranged so as to abut against the side surface of the sensor substrate opposite to the position where the strain-sensitive resistor is attached, and one leg of the bedding is placed substantially at the center of the upper surface. And a sensor case cover having an opening for exposing an upper surface of the pressure body and covering an upper surface opening of the sensor case, wherein the strain-sensitive resistor of the pressure-sensitive portion of the sensor substrate is provided. The body and the circuit part A voltage dividing resistor formed of the same material as the strain-sensitive resistor of the pressure-sensitive portion, wherein the voltage-dividing resistor is connected to the circuit portion by a conductor pattern wired so as not to contact the protrusion of the sensor case; A floor detecting device provided with an arithmetic circuit for calculating and outputting outputs of four voltage dividing circuits each including the strain-sensitive resistor and the voltage dividing resistor.